2,967 research outputs found

    COMMUTE: Cubesat Swarm Orbital Maneuvers for a Mission to Study Uranus’ aTmospheric Environment

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    Following recommendations from the 2023-2032 Planetary Science and Astrobiology Decadal Survey, new mission concepts are being developed with the focus of launching Uranus’ exploration missions in the early 2030s. To minimize both fuel consumption and cruise time on our way to Uranus, we propose a Jupiter-Uranus gravity assist trajectory using a Falcon Heavy Expendable Launcher to deliver a 3000 kg spacecraft to Uranus orbit in under seven years. The spacecraft will be composed of a mothership of 2000 kg wet mass and a swarm of CubeSats with a combined wet mass of 1000 kg. Using the ephemerides data of Earth, Jupiter and Uranus, and numerical solutions to the Lambert’s problem for a Jupiter flyby, we found that, with an initial launch window around April 15th, 2032, we reach Jupiter’s sphere of influence and perform a gravitational slingshot maneuver on December 31st, 2034, allowing the spacecraft to reach Uranus on December 31st, 2038. This proposed mission trajectory reaches Uranus with a relatively short cruise period of seven years, compared to the 13-year transfer period of the mission plan detailed in the decadal survey. This shorter transfer time could allow for significant extensions of the scientific mission nominal operations period and, potentially, reduce the cost of the overall mission. The swarm of 16 CubeSats of approximately 62 kg each will be divided into 4 groups of 4 identical spacecraft. Each group will be equipped with specialized instrumentation, exploring Uranus more extensively and performing planned plunges into its atmosphere while using the mothership as a communications relay with the Earth. This research demonstrates that a CubeSat swarm mission to Uranus can be not only viable, but also a fuel and cruise time optimization opportunity, delivering 16 exploration spacecraft to Uranus in under seven years

    Computer-Aided 2D and 3D quantification of human stem cell fate from in vitro samples using Volocity high performance image analysis software

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    AbstractAccurate automated cell fate analysis of immunostained human stem cells from 2- and 3-dimensional (2D-3D) images would improve efficiency in the field of stem cell research. Development of an accurate and precise tool that reduces variability and the time needed for human stem cell fate analysis will improve productivity and interpretability of the data across research groups. In this study, we have created protocols for high performance image analysis software Volocity® to classify and quantify cytoplasmic and nuclear cell fate markers from 2D-3D images of human neural stem cells after in vitro differentiation. To enhance 3D image capture efficiency, we optimized the image acquisition settings of an Olympus FV10i® confocal laser scanning microscope to match our quantification protocols and improve cell fate classification. The methods developed in this study will allow for a more time efficient and accurate software based, operator validated, stem cell fate classification and quantification from 2D and 3D images, and yield the highest ≥94.4% correspondence with human recognized objects

    Peripheral Blood Cell Counts as Potential Biomarkers for Alzheimer\u27s Disease: A Look at Polygenetic Risk Scores

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    Blood-based biomarkers for neurodegenerative illnesses such as Alzheimer\u27s disease (AD) have been extensively researched. Alzheimer\u27s disease (AD) is a progressive neurological illness whose progression has been ascribed to gene expression. However, the pathophysiology of these disorders and its relationship to other abnormalities remain unknown. AD has been connected to PBCs, which include erythrocytes, platelets, and leukocytes and have a complicated interaction with the brain system. The pathogenesis of PBCs has been related to a negative influence on established neurodegenerative illnesses such as Alzheimer\u27s. Candidate gene association studies have become more common as progress in mapping the human genome has increased their viability. The plurality of candidate genes were selected based on their function or expression in disease-related systems (e.g., dopamine neurotransmitter systems), and this strategy is crucial for defining the nature of internal disturbance. It has increasingly been postulated that, in addition to cell-cell signaling inside the brain, dynamic crosstalk between the brain and systematic mechanisms such as circulation of blood cells may be crucial.https://digitalscholarship.unlv.edu/durep_posters/1115/thumbnail.jp

    Effects of long-term strontium ranelate treatment on vertebral fracture risk in postmenopausal women with osteoporosis

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    Vertebral fractures are a major adverse consequence of osteoporosis. In a large placebo-controlled trial in postmenopausal women with osteoporosis, strontium ranelate reduced vertebral fracture risk by 33% over 4 years, confirming the role of strontium ranelate as an effective long-term treatment in osteoporosis. INTRODUCTION: Osteoporotic vertebral fractures are associated with increased mortality, morbidity, and loss of quality-of-life (QoL). Strontium ranelate (2 g/day) was shown to prevent bone loss, increase bone strength, and reduce vertebral and peripheral fractures. The preplanned aim of this study was to evaluate long-term efficacy and safety of strontium ranelate. METHODS: A total of 1,649 postmenopausal osteoporotic women were randomized to strontium ranelate or placebo for 4 years, followed by a 1-year treatment-switch period for half of the patients. Primary efficacy criterion was incidence of patients with new vertebral fractures over 4 years. Lumbar bone mineral density (BMD) and QoL were also evaluated. RESULTS: Over 4 years, risk of vertebral fracture was reduced by 33% with strontium ranelate (risk reduction = 0.67, p < 0.001). Among patients with two or more prevalent vertebral fractures, risk reduction was 36% (p < 0.001). QoL, assessed by the QUALIOST(R), was significantly better (p = 0.025), and patients without back pain were greater (p = 0.005) with strontium ranelate than placebo over 4 years. Lumbar BMD increased over 5 years in patients who continued with strontium ranelate, while it decreased in patients who switched to placebo. Emergent adverse events were similar between groups. CONCLUSION: In this 4- and 5-year study, strontium ranelate is an effective and safe treatment for long-term treatment of osteoporosis in postmenopausal women

    HER3 and downstream pathways are involved in colonization of brain metastases from breast cancer

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    Introduction: Metastases to the brain from breast cancer have a high mortality, and basal-like breast cancers have a propensity for brain metastases. However, the mechanisms that allow cells to colonize the brain are unclear.Methods: We used morphology, immunohistochemistry, gene expression and somatic mutation profiling to analyze 39 matched pairs of primary breast cancers and brain metastases, 22 unmatched brain metastases of breast cancer, 11 non-breast brain metastases and 6 autopsy cases of patients with breast cancer metastases to multiple sites, including the brain.Results: Most brain metastases were triple negative and basal-like. the brain metastases over-expressed one or more members of the HER family and in particular HER3 was significantly over-expressed relative to matched primary tumors. Brain metastases from breast and other primary sites, and metastases to multiple organs in the autopsied cases, also contained somatic mutations in EGFR, HRAS, KRAS, NRAS or PIK3CA. This paralleled the frequent activation of AKT and MAPK pathways. in particular, activation of the MAPK pathway was increased in the brain metastases compared to the primary tumors.Conclusions: Deregulated HER family receptors, particularly HER3, and their downstream pathways are implicated in colonization of brain metastasis. the need for HER family receptors to dimerize for activation suggests that tumors may be susceptible to combinations of anti-HER family inhibitors, and may even be effective in the absence of HER2 amplification (that is, in triple negative/basal cancers). However, the presence of activating mutations in PIK3CA, HRAS, KRAS and NRAS suggests the necessity for also specifically targeting downstream molecules.Ludwig Institute of Cancer ResearchNational Breast Cancer FoundationUniv Queensland, Clin Res Ctr, Brisbane, Qld 4029, AustraliaQueensland Inst Med Res, Brisbane, Qld 4006, AustraliaUniversidade Federal de São Paulo, EPM, Dept Anat Patol, BR-04024000 São Paulo, BrazilGriffith Univ, Brisbane, Qld 4011, AustraliaUniv Queensland, Ctr Magnet Resonance, Brisbane, Qld 4072, AustraliaEijkman Inst, Jakarta 10430, IndonesiaInst Nacl Canc, Dept Patol, BR-20230130 Rio de Janeiro, BrazilLab Salomao & Zoppi, Dept Patol, BR-04104000 São Paulo, BrazilCharles Univ Prague, Fac Med, Dept Pathol, Plzen 30605, Czech RepublicUniv Sydney, Inst Clin Pathol & Med Res, Sydney W Area Hlth Serv, Sydney, NSW 2145, AustraliaUniv Sydney, Westmead Millennium Inst, Sydney W Area Hlth Serv, Sydney, NSW 2145, AustraliaPeter MacCallum Canc Ctr, Dept Pathol, Melbourne, Vic 3002, AustraliaUniv Queensland, Queensland Brain Inst, Brisbane, Qld 4072, AustraliaRoyal Brisbane & Womens Hosp, Brisbane, Qld 4029, AustraliaUniversidade Federal de São Paulo, EPM, Dept Anat Patol, BR-04024000 São Paulo, BrazilWeb of Scienc

    Search for New Physics in e mu X Data at D0 Using Sleuth: A Quasi-Model-Independent Search Strategy for New Physics

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    We present a quasi-model-independent search for the physics responsible for electroweak symmetry breaking. We define final states to be studied, and construct a rule that identifies a set of relevant variables for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in those variables and quantifies the significance of any detected excess. After demonstrating the sensitivity of the method, we apply it to the semi-inclusive channel e mu X collected in 108 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV at the D0 experiment during 1992-1996 at the Fermilab Tevatron. We find no evidence of new high p_T physics in this sample.Comment: 23 pages, 12 figures. Submitted to Physical Review

    Search For Heavy Pointlike Dirac Monopoles

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    We have searched for central production of a pair of photons with high transverse energies in ppˉp\bar p collisions at s=1.8\sqrt{s} = 1.8 TeV using 70pb170 pb^{-1} of data collected with the D\O detector at the Fermilab Tevatron in 1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of 610,870,or1580GeV/c2610, 870, or 1580 GeV/c^2 on the mass of a spin 0, 1/2, or 1 Dirac monopole.Comment: 12 pages, 4 figure
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